/****************************************************************************** * * Module Name: nswalk - Functions for walking the ACPI namespace * *****************************************************************************/ /* * Copyright (C) 2000 - 2016, Intel Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce at minimum a disclaimer * substantially similar to the "NO WARRANTY" disclaimer below * ("Disclaimer") and any redistribution must be conditioned upon * including a substantially similar Disclaimer requirement for further * binary redistribution. * 3. Neither the names of the above-listed copyright holders nor the names * of any contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * NO WARRANTY * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGES. */ #include "acpi.h" #include "accommon.h" #include "acnamesp.h" #define _COMPONENT ACPI_NAMESPACE ACPI_MODULE_NAME ("nswalk") /******************************************************************************* * * FUNCTION: AcpiNsGetNextNode * * PARAMETERS: ParentNode - Parent node whose children we are * getting * ChildNode - Previous child that was found. * The NEXT child will be returned * * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if * none is found. * * DESCRIPTION: Return the next peer node within the namespace. If Handle * is valid, Scope is ignored. Otherwise, the first node * within Scope is returned. * ******************************************************************************/ ACPI_NAMESPACE_NODE * AcpiNsGetNextNode ( ACPI_NAMESPACE_NODE *ParentNode, ACPI_NAMESPACE_NODE *ChildNode) { ACPI_FUNCTION_ENTRY (); if (!ChildNode) { /* It's really the parent's _scope_ that we want */ return (ParentNode->Child); } /* Otherwise just return the next peer */ return (ChildNode->Peer); } /******************************************************************************* * * FUNCTION: AcpiNsGetNextNodeTyped * * PARAMETERS: Type - Type of node to be searched for * ParentNode - Parent node whose children we are * getting * ChildNode - Previous child that was found. * The NEXT child will be returned * * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if * none is found. * * DESCRIPTION: Return the next peer node within the namespace. If Handle * is valid, Scope is ignored. Otherwise, the first node * within Scope is returned. * ******************************************************************************/ ACPI_NAMESPACE_NODE * AcpiNsGetNextNodeTyped ( ACPI_OBJECT_TYPE Type, ACPI_NAMESPACE_NODE *ParentNode, ACPI_NAMESPACE_NODE *ChildNode) { ACPI_NAMESPACE_NODE *NextNode = NULL; ACPI_FUNCTION_ENTRY (); NextNode = AcpiNsGetNextNode (ParentNode, ChildNode); /* If any type is OK, we are done */ if (Type == ACPI_TYPE_ANY) { /* NextNode is NULL if we are at the end-of-list */ return (NextNode); } /* Must search for the node -- but within this scope only */ while (NextNode) { /* If type matches, we are done */ if (NextNode->Type == Type) { return (NextNode); } /* Otherwise, move on to the next peer node */ NextNode = NextNode->Peer; } /* Not found */ return (NULL); } /******************************************************************************* * * FUNCTION: AcpiNsWalkNamespace * * PARAMETERS: Type - ACPI_OBJECT_TYPE to search for * StartNode - Handle in namespace where search begins * MaxDepth - Depth to which search is to reach * Flags - Whether to unlock the NS before invoking * the callback routine * DescendingCallback - Called during tree descent * when an object of "Type" is found * AscendingCallback - Called during tree ascent * when an object of "Type" is found * Context - Passed to user function(s) above * ReturnValue - from the UserFunction if terminated * early. Otherwise, returns NULL. * RETURNS: Status * * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, * starting (and ending) at the node specified by StartHandle. * The callback function is called whenever a node that matches * the type parameter is found. If the callback function returns * a non-zero value, the search is terminated immediately and * this value is returned to the caller. * * The point of this procedure is to provide a generic namespace * walk routine that can be called from multiple places to * provide multiple services; the callback function(s) can be * tailored to each task, whether it is a print function, * a compare function, etc. * ******************************************************************************/ ACPI_STATUS AcpiNsWalkNamespace ( ACPI_OBJECT_TYPE Type, ACPI_HANDLE StartNode, UINT32 MaxDepth, UINT32 Flags, ACPI_WALK_CALLBACK DescendingCallback, ACPI_WALK_CALLBACK AscendingCallback, void *Context, void **ReturnValue) { ACPI_STATUS Status; ACPI_STATUS MutexStatus; ACPI_NAMESPACE_NODE *ChildNode; ACPI_NAMESPACE_NODE *ParentNode; ACPI_OBJECT_TYPE ChildType; UINT32 Level; BOOLEAN NodePreviouslyVisited = FALSE; ACPI_FUNCTION_TRACE (NsWalkNamespace); /* Special case for the namespace Root Node */ if (StartNode == ACPI_ROOT_OBJECT) { StartNode = AcpiGbl_RootNode; } /* Null child means "get first node" */ ParentNode = StartNode; ChildNode = AcpiNsGetNextNode (ParentNode, NULL); ChildType = ACPI_TYPE_ANY; Level = 1; /* * Traverse the tree of nodes until we bubble back up to where we * started. When Level is zero, the loop is done because we have * bubbled up to (and passed) the original parent handle (StartEntry) */ while (Level > 0 && ChildNode) { Status = AE_OK; /* Found next child, get the type if we are not searching for ANY */ if (Type != ACPI_TYPE_ANY) { ChildType = ChildNode->Type; } /* * Ignore all temporary namespace nodes (created during control * method execution) unless told otherwise. These temporary nodes * can cause a race condition because they can be deleted during * the execution of the user function (if the namespace is * unlocked before invocation of the user function.) Only the * debugger namespace dump will examine the temporary nodes. */ if ((ChildNode->Flags & ANOBJ_TEMPORARY) && !(Flags & ACPI_NS_WALK_TEMP_NODES)) { Status = AE_CTRL_DEPTH; } /* Type must match requested type */ else if (ChildType == Type) { /* * Found a matching node, invoke the user callback function. * Unlock the namespace if flag is set. */ if (Flags & ACPI_NS_WALK_UNLOCK) { MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE); if (ACPI_FAILURE (MutexStatus)) { return_ACPI_STATUS (MutexStatus); } } /* * Invoke the user function, either descending, ascending, * or both. */ if (!NodePreviouslyVisited) { if (DescendingCallback) { Status = DescendingCallback (ChildNode, Level, Context, ReturnValue); } } else { if (AscendingCallback) { Status = AscendingCallback (ChildNode, Level, Context, ReturnValue); } } if (Flags & ACPI_NS_WALK_UNLOCK) { MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE); if (ACPI_FAILURE (MutexStatus)) { return_ACPI_STATUS (MutexStatus); } } switch (Status) { case AE_OK: case AE_CTRL_DEPTH: /* Just keep going */ break; case AE_CTRL_TERMINATE: /* Exit now, with OK status */ return_ACPI_STATUS (AE_OK); default: /* All others are valid exceptions */ return_ACPI_STATUS (Status); } } /* * Depth first search: Attempt to go down another level in the * namespace if we are allowed to. Don't go any further if we have * reached the caller specified maximum depth or if the user * function has specified that the maximum depth has been reached. */ if (!NodePreviouslyVisited && (Level < MaxDepth) && (Status != AE_CTRL_DEPTH)) { if (ChildNode->Child) { /* There is at least one child of this node, visit it */ Level++; ParentNode = ChildNode; ChildNode = AcpiNsGetNextNode (ParentNode, NULL); continue; } } /* No more children, re-visit this node */ if (!NodePreviouslyVisited) { NodePreviouslyVisited = TRUE; continue; } /* No more children, visit peers */ ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode); if (ChildNode) { NodePreviouslyVisited = FALSE; } /* No peers, re-visit parent */ else { /* * No more children of this node (AcpiNsGetNextNode failed), go * back upwards in the namespace tree to the node's parent. */ Level--; ChildNode = ParentNode; ParentNode = ParentNode->Parent; NodePreviouslyVisited = TRUE; } } /* Complete walk, not terminated by user function */ return_ACPI_STATUS (AE_OK); }